<htmL>
<body>
<form action="login2">
    code:<input type="text" name="code" id ="code"><br>
    <input type="submit">
</form>
</body>
<script  src="jquery/jquery-3.3.1.min.js"></script>
<Script language="javascript">
   // function GetRequest() {
        var url = location.search; //获取url中"?"符后的字串
        var theRequest = new Object();
        if (url.indexOf("?") != -1) {
            var str = url.substr(1);
            strs = str.split("&");
            for(var i = 0; i < strs.length; i ++) {
                theRequest[strs[i].split("=")[0]]=unescape(strs[i].split("=")[1]);
            }
        }
        $("#code").val(theRequest.code);
   /*     return theRequest;
    }*/
</script>
</htmL>